<template>
  <div>
    <!-- 无id时, 可以使用index(反正也是就地更新) -->
    <div class="box" style="display: inline-block" v-for="(item, index) in arr" :key="index">
      <input type="checkbox" v-model="choose" :value="item" />
      <span>{{ item }}</span>
    </div>
    <p>你选中的元素, 累加的值和为: {{sum}} </p>
  </div>
</template>

<script>
export default {
  data() {
    return {
     arr:[9, 15, 19, 25, 29, 31, 48, 57, 62, 79, 87],
     choose:[]
    }
  },
  computed:{
    sum(){
      if(this.choose.length==0) return 0
      return this.choose.reduce((preValue, curValue) => preValue + curValue)
    }
  }
}
</script>

<style>
.box{
  margin-top: 10px;
  margin-left: 20px;
}
.box span {
  margin-left: 10px;
}
</style>